Commit message: Fix oobread in dyldcache ##crash

* Reported by @hdthky via huntr.dev
* Reproducers: poc1
* BountyID: 8ae2c61a-2220-47a5-bfe8-fe6d41ab1f82
CVE: CVE-2022-1244
CWE: CWE-703
Vulnerability description: heap-buffer-overflow in GitHub repository radareorg/radare2 prior to 5.6.8. This vulnerability is capable of inducing denial of service.

Project: radare2

static RList *create_cache_bins(RBinFile *bf, RDyldCache *cache) {
	RList *bins = r_list_newf ((RListFree)free_bin);
	ut16 *depArray = NULL;
	cache_imgxtr_t *extras = NULL;
	if (!bins) {
		return NULL;
	}

	char *target_libs = NULL;
	RList *target_lib_names = NULL;
	int *deps = NULL;
	target_libs = r_sys_getenv ("R_DYLDCACHE_FILTER");
	if (target_libs) {
		target_lib_names = r_str_split_list (target_libs, ":", 0);
		if (!target_lib_names) {
			r_list_free (bins);
			return NULL;
		}
		deps = R_NEWS0 (int, cache->hdr->imagesCount);
		if (!deps) {
			r_list_free (bins);
			r_list_free (target_lib_names);
			return NULL;
		}
	}

	ut32 i;
	for (i = 0; i < cache->n_hdr; i++) {
		cache_hdr_t *hdr = &cache->hdr[i];
		ut64 hdr_offset = cache->hdr_offset[i];
		ut32 maps_index = cache->maps_index[i];
		cache_img_t *img = read_cache_images (cache->buf, hdr, hdr_offset);
		if (!img) {
			goto next;
		}

		ut32 j;
		if (target_libs) {
			HtPU *path_to_idx = NULL;
			if (cache->accel) {
				depArray = R_NEWS0 (ut16, cache->accel->depListCount);
				if (!depArray) {
					goto next;
				}

				if (r_buf_fread_at (cache->buf, cache->accel->depListOffset, (ut8*) depArray, "s", cache->accel->depListCount) != cache->accel->depListCount * 2) {
					goto next;
				}

				extras = read_cache_imgextra (cache->buf, hdr, cache->accel);
				if (!extras) {
					goto next;
				}
			} else {
				path_to_idx = create_path_to_index (cache->buf, img, hdr);
			}

			for (j = 0; j < hdr->imagesCount; j++) {
				bool printing = !deps[j];
				char *lib_name = get_lib_name (cache->buf, &img[j]);
				if (!lib_name) {
					break;
				}
				if (strstr (lib_name, "libobjc.A.dylib")) {
					deps[j]++;
				}
				if (!r_list_find (target_lib_names, lib_name, string_contains)) {
					R_FREE (lib_name);
					continue;
				}
				if (printing) {
					eprintf ("FILTER: %s\n", lib_name);
				}
				R_FREE (lib_name);
				deps[j]++;

				if (extras && depArray) {
					ut32 k;
					for (k = extras[j].dependentsStartArrayIndex; depArray[k] != 0xffff; k++) {
						ut16 dep_index = depArray[k] & 0x7fff;
						deps[dep_index]++;

						char *dep_name = get_lib_name (cache->buf, &img[dep_index]);
						if (!dep_name) {
							break;
						}
						if (printing) {
							eprintf ("-> %s\n", dep_name);
						}
						free (dep_name);
					}
				} else if (path_to_idx) {
					carve_deps_at_address (cache, img, path_to_idx, img[j].address, deps, printing);
				}
			}

			ht_pu_free (path_to_idx);
			R_FREE (depArray);
			R_FREE (extras);
		}

		for (j = 0; j < hdr->imagesCount; j++) {
			if (deps && !deps[j]) {
				continue;
			}
			ut64 pa = va2pa (img[j].address, hdr->mappingCount, &cache->maps[maps_index], cache->buf, 0, NULL, NULL);
			if (pa == UT64_MAX) {
				continue;
			}
			ut8 magicbytes[4];
			r_buf_read_at (cache->buf, pa, magicbytes, 4);
			int magic = r_read_le32 (magicbytes);
			switch (magic) {
			case MH_MAGIC_64:
			{
				char file[256];
				RDyldBinImage *bin = R_NEW0 (RDyldBinImage);
				if (!bin) {
					goto next;
				}
				bin->header_at = pa;
				bin->hdr_offset = hdr_offset;
				bin->symbols_off = resolve_symbols_off (cache, pa);
				bin->va = img[j].address;
				if (r_buf_read_at (cache->buf, img[j].pathFileOffset, (ut8*) &file, sizeof (file)) == sizeof (file)) {
					file[255] = 0;
					char *last_slash = strrchr (file, '/');
					if (last_slash && *last_slash) {
						if (last_slash > file) {
							char *scan = last_slash - 1;
							while (scan > file && *scan != '/') {
								scan--;
							}
							if (*scan == '/') {
								bin->file = strdup (scan + 1);
							} else {
								bin->file = strdup (last_slash + 1);
							}
						} else {
							bin->file = strdup (last_slash + 1);
						}
					} else {
						bin->file = strdup (file);
					}
				}
				r_list_append (bins, bin);
				break;
			}
			default:
				eprintf ("Unknown sub-bin\n");
				break;
			}
		}
next:
		R_FREE (depArray);
		R_FREE (extras);
		R_FREE (img);
	}
	if (r_list_empty (bins)) {
		r_list_free (bins);
		bins = NULL;
	}
	R_FREE (deps);
	R_FREE (target_libs);
	r_list_free (target_lib_names);
	return bins;
}